The present invention relates to adjustable pumps in general. More particularly, this invention relates to control devices for adjustable pumps, where it is desired that the product of the lifting pressure and lifting volume times flow be kept constant, independent of the driving speed of the pump.
Regulating systems for maintaining the delivered hydraulic power constant are known in the art. The disadvantage of these otherwise satisfactory systems is that their application possibilities are limited in that an adjusting process is required for each type of the pump and for each desired product of the lifting pressure and lifting volume, this causing undesired expenses. Furthermore, the application of such conventional regulating systems for the pumps with a small adjustment path is not often possible.